Stormwater Innovations: Capturing Urban Microplastics

Microplastics are a growing area of concern in our urban catchments – and stormwater runoff has been ‘widely identified as an important transport mechanism for microplastic pollution on land to marine environments.’¹

The downstream conveyance of microplastics, and larger plastics such as bottles, leads to accumulation in our riverine and marine environments. This results in phenomena like the Great Pacific Garbage Patch, an area of marine plastic three times the size of France or 1,600,000 square kilometres.

Plastic pollution persists in our waterways and oceans with degradation timelines ranging from five years for cigarette butts to five hundred years for plastic bottles. As these plastics degrade, they don’t just disappear – they slowly fragment into smaller and smaller plastics and form microplastics.^2,3

Stormwater has been shown to contain microplastics, as contaminants from impervious surfaces are picked up by runoff in urban areas. These are comprised of a range of polymers with studies showing tyre wear pollutants (TWPs) accounting for up to 95% of particulates in sites such as car parks – and various plastic compounds like polypropylene (PP), polystyrene (PS) and polyethylene terephthalate (PET).³

Stormwater Infrastructure to Tackle Microplastics

Atlan Stormwater’s collaborative research and development has shown the efficacy of our water quality solutions for capturing microplastics in urban catchments – which includes Floating Treatment Wetlands, StormSack, and Atlan BaffleBox.

Meeting a growing demand for water quality solutions that treat emerging pollutants, our ongoing research reflects our goals as #ZeroPollutionAmbassadors to capture pollution at the source.

Demonstrating the innovative filtration capabilities of the StormSack, our study revealed the removal of 35% to 88% of microplastic concentration – varying according to site variables such as traffic patterns and road surface3. This was supported by reduced concentrations of microplastics in stormwater treated by nearby Floating Wetlands.

Broadening our range of microplastic removal solutions, the SQIDEP verification (Stormwater Quality Improvement Device Evaluation Protocol) of the Atlan BaffleBox has also shown treatment efficiencies for 66% of microplastics. Stormwater Australia is the custodian of this framework, which involves independent testing and peer-review by stormwater academics, engineers and professionals to evaluate device performance.

Our research joins a comprehensive body of evidence that stormwater without proper treatment contributes significantly to microplastics in our waterways – and their inevitable transport to our shared lakes, rivers, and seas.

From gross pollutants to microscopic contaminants – Atlan is committed to developing generational assets that meet our community needs for sustainable development. Together, we can enhance pollution removal outcomes and protect our waterways.